Line connectors of above mentioned type serve for connecting at least two media lines to one another or for the attachment connection of at least one line to an arbitrary assembly. Here, line connectors and media lines of said type can be used in particular in motor vehicles for media which, on account of their freezing point, tend to freeze even at relatively high ambient temperatures. This can cause certain functions to be adversely affected. This is the case for example with water lines for the windshield washer system, and above all also with lines for an aqueous urea solution which is used as a NOx reduction additive for diesel engines with so-called SCR catalytic converters. It is therefore possible at low temperatures for electrical heating means to be activated in order to prevent freezing or to unfreeze the already-frozen medium.
A line connector of the stated type is described in WO 2007/073286 A1. Here, an electrical heating device is fastened to the outside of the fluid connector by means of a clip element. In a transition region between the fluid connector, which is designed as a plug part of a fluid plug connection, and the fluid line, a sleeve-shaped transition piece is provided so as to adjoin the region of the heating device, which sleeve-shaped transition piece is arranged between the fluid connector and one end of a protective tube which surrounds the fluid line. The heating device is therefore exposed and unprotected in the outer region of the fluid connector. Formed between the line, which is likewise equipped with electrical heating means, and the transition piece is a hollow chamber which also serves to hold electrical connections of the heating means. The connections are accommodated only loosely in said hollow chamber, and they are therefore protected only to an insufficient extent against mechanical and other loading. As a result of the loose, undefined arrangement, the electrical connections could come into contact with one another and possibly cause a short circuit. Furthermore, the production and assembly of the known media line is difficult.
The present invention is based on the object of creating a line connector of the stated type which, while being simple to produce in a reliable process, ensures good and permanently reliable performance characteristics. It is also sought to provide an assembled line for the same purpose.
According to the invention, the benefits are achieved firstly by means of a casing which surrounds the fluid connector at least in the region of the heating means, with the casing having a tubular branch for electrical supply cables for the heating means. In this way, the heating means of the fluid connector, which heating means preferably at least partially surround the fluid duct and are formed in particular by at least one heat conductor which runs over the outer circumference of the fluid connector, are protected effectively from external influences. Furthermore, additional thermal insulation to the outside is also obtained. It is thus possible, by means of an air gap formed within the casing, to obtain a good and uniform temperature distribution. An at least partial encapsulation likewise contributes to thermal insulation. It is also advantageous if the casing is also designed to surround an end region of a fluid line attached to the attachment section and preferably also to surround an end region of a tubular sheathing of the fluid line. Said sheathing is formed in particular by a corrugated tube whose end region is fixed in the casing preferably in a positively locking fashion. All the required electrical connections between the heating means of the fluid connector, external supply cables and preferably provided heating means of the fluid line can be accommodated in a well-protected manner within the casing. Particularly effective protection can be obtained if the electrical connections (contact points, bared points) can be embedded in a plastic molding compound by extrusion coating and/or encapsulation. The external supply cables can then be guided to the outside via the casing branch according to the invention. Here, it is advantageous for the branch to be designed to hold an end region of a tubular cable sheath, which is in particular likewise formed by a corrugated tube, for the supply cables in a positively locking fashion. It may alternatively also be provided that the branch has an electrical connection element, in particular in the form of a plug connection for external supply cables. Here, the connection element is connected within the casing to the heating means of the fluid connector and if appropriate to heating means of the fluid line.
In one advantageous refinement of the invention, the branch is formed as a separate branch part which is or can be connected to the casing. Said design of the branch as a separate branch part advantageously results in different application possibilities. It is thus possible for the casing to fundamentally also be used without a branch. If required, the branch part may be fastened in the region of an opening of the casing. The opening may be prefabricated or else formed by removing a region of the casing. Here, a wall part may be broken out via predetermined breaking points. The branch part is fastened in particular by latching means. The branch part may however also be connected to the casing in a positively locking fashion. In the case of an acute or obtuse branch angle with respect to the line axis, and also in the case of a branch approximately parallel to and offset with respect to the line axis, it is also advantageously possible for the branch part to be able to be mounted in different orientations of its branch axis.
The following description describe further advantageous embodiment features of the invention.